From the search tab in the Explorer sidebar, you can search across all the scripts in your workspace.
Searching for a single word is straightforward. If you search for the word candy, you'll get all the scripts that contain the word candy. The more times the word appears in a script, the higher that script will be in the results.
If you search for more than one word and the none of the words are on quotation marks, phrase matches are prioritized but individual word matches are also returned. For example, if you search for the words candy hearts without quotation marks, the top results will be scripts that contain the exact phrase candy hearts. After that, you'll see scripts that contain both the word candy and the word hearts but not as a phrase. Last, you'll see scripts that contain just the word candy or just the word hearts.
Searches for phrases in quotation marks
If you search for "candy hearts" with the words in quotation marks, you'll only get scripts that contain the exact phrase "candy hearts."
Searches look at script titles as well as the body of the document, and capitalization never matters.